1. Field of the Invention
The present invention relates to a miniature fan and, more particularly, to a miniature fan with a reduced axial height and with a reduced volume.
2. Description of the Related Art
FIGS. 1 and 2 show a conventional heat-dissipating fan 8 including a housing 81 and a lid 82 mounted on top of the housing 81. The housing 81 includes a compartment 811 in which a base 812 is formed. A circuit board 83 and a coil unit 84 are mounted on the base 812. The base 812 further includes at least two positioning members 85. A shaft tube 813 is formed on a center of the base 812. A rotor 86 is rotatably coupled to the shaft tube 813 and rotatably received in the compartment 811. A magnet 861 is mounted to an inner side of the rotor 86 and interacts with the coil unit 84 to drive the rotor 86 to rotate. The heat-dissipating fan 8 can be mounted on differing electronic devices or equipment for heat-dissipating purposes. However, the axial heights of the circuit board 83 and the coil unit 84 outside of the circuit board 83 cause limitation to the reduction in the overall axial height of the heat-dissipating fan. As a result, it is difficult to achieve a light, compact design of the heat-dissipating fan 8 and, thus, it is difficult to mount the heat-dissipating fan 8 in miniature electronic devices or equipment.
FIGS. 3 and 4 show another conventional heat-dissipating fan 9 including a base 91, an impeller 92, a disc-like magnet 93, and a shaft 94. The base 91 includes a hole 911 for rotatably receiving an end of the shaft 94. The other end of the shaft 94 is coupled to the impeller 92 that has a plurality of blades 921. A coil unit 912 is mounted on the base 91. The heat-dissipating fan 9 can be mounted on differing electronic devices or equipment for heat-dissipating purposes. An example of such a heat-dissipating fan is disclosed in Taiwan Patent No. 1293106. However, the axial heights of the base 91 and the coil unit 912 cause limitation to the reduction in the overall axial height of the heat-dissipating fan 9. As a result, it is difficult to achieve a light, compact design of the heat-dissipating fan 9 and, thus, it is difficult to mount the heat-dissipating fan 9 in miniature electronic devices or equipment.
Thus, a need exists for a miniature fan with a reduced axial height and with a reduced volume to meet the design trend of compactness and miniaturization.